I imported the MediaPlayer framework and used MPMusicPlayerPlayParameters in my SwiftUI project. While the app is launching, If the app is built by Xcode 14.3.1 or a newer version, it instantly crashes on a simulator or on a real device. This problem persists on iOS 16.0 to 16.4. (I haven't tried iOS 15 or below) I also tried to build and run the app with Xcode 15 - beta 4 however it still crashes. Because of this reason, I archive and submit to App Store with Xcode 14.2. (the built made by Xcode 14.2 works perfectly!!) Here is the error message: dyld[17235]: Symbol not found: _$sSo27MPMusicPlayerPlayParametersCSe05MediaB0Mc Referenced from: <77FEF170-9C51-3580-8F8B-2ADD2F1B3FD1> /Users/[UserName]/Library/Developer/CoreSimulator/Devices/72CE26D8-4DD4-4319-B0C7-DE52D6645875/data/Containers/Bundle/Application/C808623F-5372-40F0-907F-E86E12AE6EDD/[AppName].app/[AppName] Expected in: <06F636E1-695C-34F1-809D-7CA24F67AFE9> /Library/Developer/CoreSimulator/Volumes/iOS_20B72/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 16.1.simruntime/Contents/Resources/RuntimeRoot/System/Library/Frameworks/MediaPlayer.framework/MediaPlayer I believe this is Apple related issue however if there is any way that can fix the issue, please let me know.

Hi, Is there any reasonable way to use MusicKit on the Vision Pro simulator. I have been unable to get anything working and I was wondering if the situation is the same as iOS etc where you need a physical device to test the app.

Planning to create a Music Game App similar to Guitar Hero kind of, and I am planning to use songs from beginner producers (They don't have any Publishers or Distributors). If I get their legal concent through a contract to use their songs, does Apple allow to have Music that is not from Itunes if I get the legal license from the producer to use their songs in my app? Will apple allow songs that don't have Publishers or Distributors, or in the App review stage they will flag it and cause an issue for me?

If a user has only added one song from an album in its library, the library album endpoint (/me/library/albums) will return this album. It does not make sense because the user did not add the full album to its library, only one song. Note that the Apple Music app is doing the same in its Library > Albums section. How to retrieve only those albums which have been added ?

I'm currently working on integrating MusicKit into my app and would like to provide a seamless user experience by displaying only the songs that are available in the user's region or country. However, after going through the MusicKit documentation, I couldn't find a direct method to determine song availability based on the user's location. I wanted to inquire if there is a way to determine if a specific song or a catalog of songs is available in the user's region or country using MusicKit. It would be incredibly helpful if someone could guide me on how to achieve this or provide any insights on alternative approaches. Thank you in advance for your assistance!

Hi, My app hangs for about a second when I open the app when it's been in background phase. It doesn't hang every time, but it hangs randomly (like once in 10 times) when I open the app again. I am not able to reproduce what causes this hang. Hang Detection provides hang logs (spindump) when hang occurs. It has something to do with MusicKit as logs mention it but I cannot understand what it is. Please help me understand these logs. I am running iOS 17 beta 1 with MusicKit and ApplicationMusicPlayer. Heaviest stack for the main thread of the target process: 69 start + 2104 (dyld + 87288) [0x1b719b4f8] 69 ??? (Timed + 32864) [0x104ae8060] 69 ??? (SwiftUI + 980040) [0x19840a448] 69 ??? (SwiftUI + 1071088) [0x1984207f0] 69 ??? (SwiftUI + 1667804) [0x1984b22dc] 69 UIApplicationMain + 340 (UIKitCore + 3740336) [0x196c602b0] 69 -[UIApplication _run] + 888 (UIKitCore + 3741260) [0x196c6064c] 69 GSEventRunModal + 164 (GraphicsServices + 4644) [0x1d6199224] 69 CFRunLoopRunSpecific + 600 (CoreFoundation + 527792) [0x1947fedb0] 68 __CFRunLoopRun + 1996 (CoreFoundation + 509348) [0x1947fa5a4] 68 __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 16 (CoreFoundation + 626340) [0x194816ea4] 68 _dispatch_main_queue_callback_4CF + 44 (libdispatch.dylib + 75296) [0x19c404620] 67 _dispatch_main_queue_drain + 744 (libdispatch.dylib + 76056) [0x19c404918] 67 swift_job_runImpl(swift::Job*, swift::ExecutorRef) + 72 (libswift_Concurrency.dylib + 274348) [0x19f58cfac] 67 swift::runJobInEstablishedExecutorContext(swift::Job*) + 416 (libswift_Concurrency.dylib + 269688) [0x19f58bd78] 66 ??? (MusicKit + 4857464) [0x208aabe78] 66 ??? (MusicKit + 4856108) [0x208aab92c] 66 -[MusicKit_SoftLinking_MPMusicPlayerController nowPlayingItem] + 24 (MusicKit + 157364) [0x2086306b4] 66 -[MPMusicPlayerController nowPlayingItem] + 24 (MediaPlayer + 1358540) [0x1a681bacc] 66 -[MPMusicPlayerController _nowPlaying] + 372 (MediaPlayer + 1329552) [0x1a6814990] 66 -[MPMusicPlayerController onServer:] + 52 (MediaPlayer + 1333428) [0x1a68158b4] 63 -[MPMusicPlayerApplicationController _establishConnectionIfNeeded] + 1768 (MediaPlayer + 1553848) [0x1a684b5b8] 63 _NSXPCDistantObjectSimpleMessageSend1 + 60 (Foundation + 208348) [0x1937daddc] 63 -[NSXPCConnection _sendSelector:withProxy:arg1:] + 116 (Foundation + 208548) [0x1937daea4] 62 -[NSXPCConnection _sendInvocation:orArguments:count:methodSignature:selector:withProxy:] + 2160 (Foundation + 214664) [0x1937dc688] 62 __NSXPCCONNECTION_IS_WAITING_FOR_A_SYNCHRONOUS_REPLY__ + 16 (Foundation + 652944) [0x193847690] 62 xpc_connection_send_message_with_reply_sync + 264 (libxpc.dylib + 67488) [0x1fc00d7a0] 62 dispatch_mach_send_with_result_and_wait_for_reply + 60 (libdispatch.dylib + 127760) [0x19c411310] 62 _dispatch_mach_send_and_wait_for_reply + 540 (libdispatch.dylib + 126832) [0x19c410f70] 62 mach_msg + 24 (libsystem_kernel.dylib + 4692) [0x1da082254] 62 mach_msg_overwrite + 436 (libsystem_kernel.dylib + 83544) [0x1da095658] 62 mach_msg2_trap + 8 (libsystem_kernel.dylib + 3332) [0x1da081d04] *62 ??? (<31E57057-A9A0-3BE5-90CB-5C08E9683B34> + 217132) [0xfffffff007e0102c] Thank you. CC @JoeKun

I'm getting the following error in Xcode and I can't figure out how to fix it. Cannot load underlying module for 'MediaPlayer' I've searched Google and have come across lots of other people with similar issues whereby they're importing something and it's producing this error alongside it. https://stackoverflow.com/questions/76256875/cannot-load-underlying-module-for-scenekit https://developer.apple.com/forums/thread/115059 https://stackoverflow.com/questions/32673866/cocoapods-cannot-load-underlying-module-for-x The error is being shown inline with this bit of code: import SwiftUI import MusicKit import MediaPlayer <-- this line here I can build and run the project without issue and it disappears. But will quickly reappear again a short while later and it's very annoying. How can I resolve this please?

I've been continuing to port my app to the Mac using Catalyst, and have discovered a couple of big issues with MusicLibraryRequest which make it not particularly usable. I've submitted FBs already, but figured a forum post wouldn't hurt :) filter(matching:) functions unavailable on macOS/Catalyst - FB12301718 The first thing I noticed when building for a macOS or Catalyst target is that a couple of functions are simply not available: I'm hoping this is a bug, as these methods are crucial to being able to interact with the library. request.filter(matching: .id, equalTo:) always returns empty on Mac Catalyst - FB12301908 I have not been able to successfully retrieve an Album using a MusicLibraryRequest. The result is always empty. In the feedback, I attached a sample project that makes an unfiltered MusicLibraryRequest, then takes the first album and tries to make a new MusicLibraryRequest filtered to that album's ID. Fetching albums by ID using this method works just fine on iOS 17. Thanks again for all your work on bringing these capabilities to the Mac!

Is there a way to get the user name after login if I use Apple Music Kit JS or using the APIs? Or can I use the music token from Apple Music kit JS with Apple Sign In to get a user name? Greetings

Hi, . As my understading, I know that id: MusicItemID The unique identifier for the song. Threfore, I want to try to retreive the specific song I want by using MusicItemID : let request = MusicCatalogResourceRequest<Song>(matching: \.id, equalTo: //MusicItemID) let response = try await request.response() guard let song = response.items.first else { return } However, where can I find the MusicItemID for the song I want ? Thank you so much

Hi, I’m looking at using MusicKit in my watchOS app however I don’t seem to have any method of being able to play the audio though the recommended use of MPMusicPlayerController since it isn’t available on watchOS. This method works fine for iOS and iPadOS but not watchOS which seems bizarre considering we have full access to MusicKit but no way to actually play any audio. I’m trying to build an app that includes Apple Music through MusicKit but don’t have any way to actually play the audio. Is there a technical reason for this and if so is there any other way to play audio from MusicKit on watchOS. The docs for MPMusicPlayerController can be found here: https://developer.apple.com/documentation/mediaplayer/mpmusicplayercontroller

I'm making a request to get 10 artists with their top songs at once, but for some artists it will always fail with a 504. The response is also in HTML which leads to a decoding error. This is my code var request = MusicCatalogResourceRequest<Artist>(matching: \.id, memberOf: ids) request.properties = properties let response = try await request.response() where ids is MusicItemId. Below I have an input which will always fail 100% of the time, even when retried. 10 elements  - 0 : "51639"  - 1 : "331584"  - 2 : "120199"  - 3 : "45058"  - 4 : "284786497"  - 5 : "44984"  - 6 : "37299"  - 7 : "518462"  - 8 : "39525"  - 9 : "73568" Example response: [DataRequesting] Failed to parse body of response with status code Unknown (504):  <!DOCTYPE html> <html lang="en"> <head>   <style>     body {       font-family: "Helvetica Neue", "HelveticaNeue", Helvetica, Arial, sans-serif;       font-size: 15px;       font-weight: 200;       line-height: 20px;       color: #4c4c4c;       text-align: center;     }     .section {       margin-top: 50px;     }   </style> </head> <body> <div class="section">   <h1>&#63743;</h1>   <h3>Gateway Timeout</h3>   <p>Correlation Key: WFRI6Q5HXAUJYXGNRKQ6YTBYIM</p> </div> </body> </html> I have also tried batching these into 2 requests of 5 artists instead of 1 request of 10 artists which still fails. However, I do have sets of 10 artists that work fine. Anyone know why?

Hello everyone! I am using the web version of the Apple Music Kit API, and similar to how Apple is able to produce a user's year in rewind playlist showing the most played artists/songs from a year, I am trying to replicate it for either a year or all time. I have been searching the internet for days trying to figure it out, but I've been completely stuck. I am able to make the following HTTP request successfully. GET https://api.music.apple.com/v1/me/library/songs/ which returns back the user's library of songs, but I haven't figured out how to get the play count. I have tried adding a query like such ?extend=playCount, but that doesn't work. I can see here that the Swift Music Kit API is able to extend a play count property, but I haven't been able to figure it out for Web. Ideally, I am looking for an endpoint that just shows a user's top artist/tracks similar to Spotify, however, whenever I try to use the heavy in rotation endpoint here, it always returns an empty array. The way that I have described is the long-roundabout way where I'll have to fetch each individual song and sort by playCount. But if anyone happens to know how I can do either of the options I've described, it will be truly appreciated ! I've seen other forums posts from years ago, but hopefully there's been a discovered way. Thank you!

In my Developer account under Certificates, Identifiers &amp; Profiles --&gt; Keys, I cannot add the "Media Services (MusicKit, ShazamKit) key. I have an app identifier where the "MusicKit" App Service is selected. How can I get the key to be available for this app?

Hi there, I have a related forum thread here and a Feedback Assistant ticket open, but this issue seems different. Sometime within the last 2-3 weeks, code related to MusicLibrary has stopped working. None of my code has changed. For example, the below two snippets used to work fine:  for track in newTracks {    try await MusicLibrary.shared.add(track, to: targetPlaylist)  } try await MusicLibrary.shared.edit(targetPlaylist, items: items) newTracks and items are both fetched using: try await targetPlaylist.with(.tracks, preferredSource: .catalog).tracks Using preferredSource: .catalog was a workaround used to address the issue in the aforementioned post above. All iOS 16 capable functions are decorated with: @available(iOS 16, *) or in an if block: if #available(iOS 16, *) {... What's happening is that the following is showing up in the console: 2022-11-28 23:31:11.279648+0700 MyApp[38653:6736450] [core] Attempted to register account monitor for types client is not authorized to access: {(     "com.apple.account.iTunesStore" )} 2022-11-28 23:31:11.279718+0700 MyApp[38653:6736450] [Default] <ICUserIdentityStoreACAccountBackend: 0x282adb520> Failed to register for account monitoring. err=Error Domain=com.apple.accounts Code=7 "(null)" 2022-11-28 23:31:11.279758+0700 MyApp[38653:6736450] [Default] ICUserIdentity - Unable to retrieve DSID for userIdentity=<ICUserIdentity 0x2806eb120: [Active Account: <unresolved>]> - error=Error Domain=com.apple.accounts Code=7 "(null)" These errors are not caught by a do/catch block, but I assume they are related to the issue, and I believe they have to do with MyApp trying to access things that Music Kit thinks it's not supposed to. For example, if MyApp attempts to work with a playlist that it did not create, errors would be expected, thrown errors. The thing is that I know I'm working with resources that are created by MyApp. In fact, in trying to test this, I just tried to create a playlist with the below, and the same behavior is occurring: @available(iOS 16, *) func createPlaylist2(name: String, description: String) async -> MusicKit.Playlist? {     do {         Logger.log(.info, "Creating Playlist: \(name)")         Logger.log(.shrug, "Does this work?")         let newPlaylist = try await MusicLibrary.shared.createPlaylist(name: name, description: description) // <= Things stop here!         Logger.log(.success, "New playlist created: \(newPlaylist)") // <= this isn't logged.         return newPlaylist // <= nothing is returned     } catch {         Logger.log(.error, "Could not create new playlist: \(error)") // <= no error logged.     }     return nil } The result is: 2022-11-29 00:15:01.875064+0700 MyApp[38794:6760471] [core] Attempted to register account monitor for types client is not authorized to access: {(     "com.apple.account.iTunesStore" )} 2022-11-29 00:15:01.875372+0700 MyApp[38794:6760471] [Default] <ICUserIdentityStoreACAccountBackend: 0x283005720> Failed to register for account monitoring. err=Error Domain=com.apple.accounts Code=7 "(null)" 2022-11-29 00:15:01.876677+0700 MyApp[38794:6760323] [EntityQuery] Finished executing query in 0.000999928s 2022-11-29 00:15:01.889055+0700 MyApp[38794:6760323] [EntityQuery] Finished fetching results in 0.0120001s 2022-11-29 00:15:01.891235+0700 MyApp[38794:6760329] [core] Attempted to register account monitor for types client is not authorized to access: {(     "com.apple.account.iTunesStore" )} 2022-11-29 00:15:01.891684+0700 MyApp[38794:6760329] [Default] <ICUserIdentityStoreACAccountBackend: 0x283005720> Failed to register for account monitoring. err=Error Domain=com.apple.accounts Code=7 "(null)" 📘 Creating Playlist: TEST PLAYLIST 🤷🏻‍♀️ Does this work? 2022-11-29 00:15:06.697374+0700 MyApp[38794:6760329] [] nw_path_necp_check_for_updates Failed to copy updated result (22) What's really nasty is that errors are not thrown, so they can't be caught and handled in a catch block. I know that iOS 16.1 got released around the end of October, but I really don't know what's going on here. The behavior is showing up in both prod and when testing locally. Any help would be most appreciated. @JoeKhun: Did I miss the memo?

Hello, this is building off of another post in which several other posters and I had already attempted solving the issue in hacky ways. I am using MPMusicPlayerController.applicationQueuePlayer. My end goal here is to dynamically add items to the queue when it has ended based on my application's business logic. There is no way for me to know what these items will be when I am initially setting the queue. I have an updated implementation that seems to cover most edge cases, except for a glaringly obvious one – if there is just one item in the queue, and the user skips the track via MPRemoteCommandCenter (eg. lock screen), then it does not work. Currently, when I receive a MPMusicPlayerControllerPlaybackStateDidChange notification, I run this block: if player.playbackState == .paused,            player.currentPlaybackTime == 0,            player.indexOfNowPlayingItem == 0 {             EndOfQueueManager.handle()         } In the absence of a mechanism to detect the end of the queue from the framework, I would love to add the ability to add a target to MPRemoteCommand, like you can do for AVPlayer. I have tried to do exactly that, but it does not work: MPRemoteCommandCenter.shared().nextTrackCommand.addTarget { (event) -> MPRemoteCommandHandlerStatus in         if queue.count == 1 {             EndOfQueueManager.handle() }         return .success } I already have a functioning AVPlayer implementation that achieves my goal without any compromises or edge cases. I would be very disappointed if there is no way to do this with MPMusicPlayerController – being notified about the queue ending feels like a fairly rudimentary API hook.

I am trying to offer my users a wide variety of playlists, like Apple Music does in the "explore" section. I fetched the charting playlists for the current storefront, but that's as far as I get. For example, I fetch the top charts genres first. If a user selects a genre I want to display the playlists for this genre, so I call the charts endpoint with the genre as the id but I can't get a response. path = "/v1/catalog/\(storefrontID)/charts" components.queryItems = [ URLQueryItem(name: "types", value: "playlists"), URLQueryItem(name: "chart", value: "most-played") ] if let id = id { let genreQuery = URLQueryItem(name: "genre", value: id) components.queryItems?.append(genreQuery) } Even weirder, I get exactly one genre "Musik" (which isn't a genre) with identifier "34" and storefrontId "de" where it works and I get my playlists. All other genre return empty responses. I try to use AppleMusic API with MusicKit as an addition, but there doesn't seem to be a solution for this problem either.

Hello! I am having trouble setting start times for songs when using the ApplicationMusicPlayer. When I initialize a new MusicPlayer.Queue.Entry using the following constructor, I am seeing strange results: init( _ playableMusicItem: PlayableMusicItem, startTime: TimeInterval? = nil, endTime: TimeInterval? = nil ) It appears that any value I provide for startTime is also applied to the endTime. For example: MusicPlayer.Queue.Entry(playable, startTime: TimeInterval(30), endTime: TimeInterval(183)) provides the following console output: MusicPlayer.Queue.Entry(id: "3D6A3DA3-595E-4657-8DBA-DDD245BBB7EF", transientItem: PlayableMusicItem, startTime: 30.0, endTime: 30.0) I have also tried setting the endTime to nil with the same result. Does anyone have any experience setting start times for songs using the MusicKit ApplicationMusicPlayer? Any feedback is greatly appreciated!

Hi there, tl;dr: What's the best way to get all tracks (with catalog IDs) from a playlist that has more than 100 tracks, using MusicLibraryRequest. I'm doing something dumb, not understanding something, and possibly both. I've got an existing, kinda okay function that uses the MusicDataRequest and the Apple Music API to fetch all tracks from a playlist, with pagination like this: func getTracksFromAppleMusicLibraryPlaylist(playlist: AppleMusicPlaylist) async throws -> [MusicKit.Track]? {     var tracksToReturn: [MusicKit.Track] = []     var libraryTracks: [AppleMusicLibraryTrack] = []     @Sendable     func fetchTracks(playlist: AppleMusicPlaylist, offset: Int) async -> AppleMusicPlaylistFetchResponse? {         do {             let playlistId = playlist.id             var playlistRequestURLComponents = URLComponents()             playlistRequestURLComponents.scheme = "https"             playlistRequestURLComponents.host = "api.music.apple.com"             playlistRequestURLComponents.path = "/v1/me/library/playlists/\(playlistId)/tracks"             playlistRequestURLComponents.queryItems = [                 URLQueryItem(name: "include", value: "catalog"),                 URLQueryItem(name: "limit", value: "100"),                 URLQueryItem(name: "offset", value: String(offset)),             ]             if let playlistRequestURL = playlistRequestURLComponents.url {                 let playlistRequest = MusicDataRequest(urlRequest: URLRequest(url: playlistRequestURL))                 let playlistResponse = try await playlistRequest.response()                 let decoder = JSONDecoder()                 // print("Get Tracks Dump")                 // print(String(data: playlistResponse.data, encoding: .utf8)!)                            let response = try decoder.decode(AppleMusicPlaylistFetchResponse.self, from: playlistResponse.data)                 return response             } else {                 print("Bad URL!")             }         } catch {             print(error)         }         return nil     }     Logger.log(.info, "Fetching inital tracks from \(playlist.attributes.name)")     if let response = await fetchTracks(playlist: playlist, offset: 0) {         if let items = response.data {             libraryTracks = items         }         if let totalItemCount = response.meta?.total {             Logger.log(.info, "There are \(totalItemCount) track(s) in \(playlist.attributes.name)")             if totalItemCount > 100 {                 let remainingItems = (totalItemCount - 100)                 let calls = remainingItems <= 100 ? 1 : (totalItemCount - 100) / 100                 Logger.log(.info, "Total items: \(totalItemCount)")                 Logger.log(.info, "Remaining items: \(remainingItems)")                 Logger.log(.info, "Calls: \(calls)")                 await withTaskGroup(of: [AppleMusicLibraryTrack]?.self) { group in                     for offset in stride(from: 100, to: calls * 100, by: 100) {                         Logger.log(.info, "Fetching additional tracks from \(playlist.attributes.name) with offset of \(offset)")                         group.addTask {                             if let response = await fetchTracks(playlist: playlist, offset: offset) {                                 if let items = response.data {                                     return items                                 }                             }                             return nil                         }                     }                     for await (fetchedTracks) in group {                         if let tracks = fetchedTracks {                             libraryTracks.append(contentsOf: tracks)                         }                     }                 }             }         }     } // props to @JoeKun for this bit of magic     Logger.log(.info, "Matching library playlist tracks with catalog tracks...")     for (i, track) in libraryTracks.enumerated() {         if let correspondingCatalogTrack = track.relationships?.catalog?.first {             tracksToReturn.append(correspondingCatalogTrack)             print("\(i) => \(track.id) corresponds to catalog track with ID: \(correspondingCatalogTrack.id).")         } else {             Logger.log(.warning, "\(i) => \(track.id) doesn't have any corresponding catalog track.")         }     }     if tracksToReturn.count == 0 {         return nil     }     return tracksToReturn } While not the most elegant, it gets the job done, and it's kinda quick due to the use of withTaskGroup .esp with playlists containing more than 100 songs/tracks. Regardless, I'm kinda stuck, trying to do something similar with the new MusicLibraryReqeust in iOS 16. The only way I can think of to get tracks from a playlist, using MusicLibraryRequest, having read the new docs, is like this: @available(iOS 16.0, *) func getAllTracksFromHugePlaylist(id: MusicItemID) async throws -> [MusicKit.Track]? {     do {         var request = MusicLibraryRequest<MusicKit.Playlist>()         request.filter(matching: \.id, equalTo: id)         let response = try await request.response()         if response.items.count > 0 {             if let tracks = try await response.items[0].with(.tracks, preferredSource: .catalog).tracks {                 Logger.log(.info, "Playlist track count: \(tracks.count)")                 return tracks.compactMap{$0}             }         }     } catch {         Logger.log(.error, "Could not: \(error)")     }     return nil } The problem with this is that .with seems to be capped at 100 songs/tracks, and I can't see any way to change that. Knowing that, I can't seem to tell MusicLibraryRequest that I want the tracks of the playlist with the initial request, where before I could use request.properties = .tracks, which I could then paginate if available. Any help setting me on the right course would be greatly appreciated.

I've just begun to dip my toes into the iOS16 waters. One of the first things that I've attempted is to edit a library playlist using: try await MusicLibrary.shared.edit(targetPlaylist, items: tracksToAdd) Where targetPlaylist is of type MusicItemCollection<MusicKit.Playlist>.Element and tracksToAdd is of type [Track] The targetPlaylist was created, using new iOS16 way, here: let newPlaylist = try await MusicLibrary.shared.createPlaylist(name: name, description: description) tracksToAdd is derived by performing a MusicLibraryRequest on a specific playlist ID, and then doing something like this: if let tracksToAdd = try await playlist.with(.tracks).tracks {    // add tracks to target playlist } My problem is that when I perform attempt the edit, I am faced with a rather sad looking crash. libdispatch.dylib`dispatch_group_leave.cold.1:     0x10b43d62c <+0>:  mov    x8, #0x0     0x10b43d630 <+4>:  stp    x20, x21, [sp, #-0x10]!     0x10b43d634 <+8>:  adrp   x20, 6     0x10b43d638 <+12>: add    x20, x20, #0xfbf          ; "BUG IN CLIENT OF LIBDISPATCH: Unbalanced call to dispatch_group_leave()"     0x10b43d63c <+16>: adrp   x21, 40     0x10b43d640 <+20>: add    x21, x21, #0x260          ; gCRAnnotations     0x10b43d644 <+24>: str    x20, [x21, #0x8]     0x10b43d648 <+28>: str    x8, [x21, #0x38]     0x10b43d64c <+32>: ldp    x20, x21, [sp], #0x10 ->  0x10b43d650 <+36>: brk    #0x1 I assume that I must be doing something wrong, but I frankly have no idea how to troubleshoot this. Any help would be most appreciated. Thanks. @david-apple?